The FBI has asked the Senate for unredacted documents it obtained from abortion providers, signaling agents may be investigating whether Planned Parenthood and other abortion providers illegally sold fetal tissue and body parts, according to sources familiar with the document request.

The request was made in recent days, the sources said, to the Senate Judiciary Committee, whose chairman, Sen. Chuck Grassley (R-Iowa), last December referred Planned Parenthood and several other abortion providers to the FBI for investigation after a lengthy probe into the transfers of fetal tissue.

Grassley said at the time that his committee had uncovered enough evidence in its final investigative report to show abortion providers had transferred tissue and body parts from aborted fetuses to firms for use in research by charging dollar amounts above their actual costs.